Molded hearing aid housing

Abstract

A method of processing an impression of a portion of a user's ear canal that produces a flexible hearing aid housing which duplicates the shape of at least a portion of that impression. A female mold is created using the previously obtained ear impression. A compliant molding material is used to form the female mold. The same material is used to form a male mold in the cavity left in the female mold when the ear impression has been removed. Subsequent to curing of the male mold, it is removed from the female mold and covered with a curable, hardenable plastic such as a UV curable acrylic. Once cured, the compliant male mold is removed leaving a rigid plastic shell whose internal volume conforms in shape to the exterior shape of the ear impression. Mandrels can be inserted into the volume to provide post molding compartments for electronic components. A matrix can be inserted into the internal region or wrapped around the mandrels or respective components. A compliant elastomer can be used to fill, under vacuum, the voids in the rigid shell. When cured, the elastomeric housing can be removed from the rigid shell and the mandrels extracted therefrom. A completed hearing aid can be formed by inserting the respective components into the housing and making the required connections.

What is claimed:  
     
       1. A hearing aid comprising: 
       a housing molded of a compliant elastomer, wherein the housing has an exterior periphery and the housing defines at least one internally formed, component carrying region, wherein the housing includes an integrally formed peripheral boundary layer which displaces the region inwardly of the housing away from the exterior periphery and wherein the depth of the boundary layer is determined, at least in part, by a matrix, the matrix comprising a porous structure, the porous structure permeated by the elastomer.  
     
     
       2. A hearing aid as in  claim 1  wherein the matrix comprises an en cell foam material. 
     
     
       3. A hearing aid as in  claim 1  which includes at least an output transducer, molded into the housing wherein the transducer is displaced inwardly of the periphery at least by a portion of the elastomer permeated matrix. 
     
     
       4. A hearing aid as in  claim 1  which includes an output transducer, inserted in a preformed region in the housing wherein that region is bounded, at least in part, by the matrix. 
     
     
       5. A hearing aid as in  claim 4  which carries an input transducer with a first orientation and wherein the output transducer has an orientation selected so as to minimize feedback. 
     
     
       6. A hearing aid as in  claim 4  wherein the output transducer is supported only at selected spaced apart locations by the housing. 
     
     
       7. A hearing aid as in  claim 6  which includes spaces between the output transducer and the preformed region. 
     
     
       8. A hearing aid as in  claim 7  wherein at least some of the spaces are filled with a gas. 
     
     
       9. A hearing aid as in  claim 1  wherein the component carrying region is defined by a mandrel removable from the housing, at least in part by deforming a portion of the elastomer. 
     
     
       10. A hearing aid as in  claim 9  which includes a receiver output tube wherein the location and orientation of the tube were established using a deformable representation of the housing. 
     
     
       11. A hearing aid as in  claim 5  wherein the transducers are oriented so as to be on the order of ninety degrees out of phase with one another. 
     
     
       12. A hearing aid as in  claim 1  wherein the housing conformably seals a portion of a user's ear canal thereby minimizing external feedback. 
     
     
       13. A hearing aid as in  claim 12  wherein the housing conforms, in response to dynamic deformation of the user's ear canal, thereby maintaining the seal. 
     
     
       14. A hearing aid as in  claim 1  having a selected surface, covered only in part by an electronic module wherein the module is displaced from direct contact with the user's ear. 
     
     
       15. A hearing aid as in  claim 1  wherein a selected surface of the housing is covered by a rigid face plate. 
     
     
       16. A hearing aid as in  claim 15  which includes a battery compartment carried on the faceplate. 
     
     
       17. A hearing aid as in  claim 15  wherein the housing carries an output transducer wherein the output transducer is displaced, at least in part, from the exterior periphery by the boundary layer. 
     
     
       18. A hearing aid as in  claim 17  which carries an input transducer adjacent to the faceplate wherein the transducers are oriented so as to be out of phase with one another. 
     
     
       19. A hearing aid as in  claim 18  which includes speech processing circuitry, comprising at least a gain element, coupled between the transducers. 
     
     
       20. A hearing aid as in  claim 1  wherein a selected component can be inserted into or removed from the housing by deforming same. 
     
     
       21. A hearing aid comprising: 
       a housing molded of a compliant elastomer, wherein the housing has a deformable exterior periphery and the housing defines at least one internally formed, component carrying region, wherein the housing includes an integrally formed, deformable, peripheral boundary layer which displaces the region inwardly of the housing away from the exterior periphery and wherein the depth of the boundary layer is determined, at least in part, by a matrix, the matrix comprising a porous structure, the porous structure permeated by the elastomer.  
     
     
       22. A hearing aid as in  claim 21  wherein the matrix comprises one of an open cell foam and a fabric. 
     
     
       23. A hearing aid as in  claim 21  which includes at least an output transducer, carried in the housing wherein the transducer is displaced inwardly of the periphery at least by a portion of the elastomer permeated matrix. 
     
     
       24. A hearing aid as in  claim 23  which carries an input transducer with a first orientation and wherein the output transducer has an orientation selected so as to minimize feedback. 
     
     
       25. A hearing aid as in  claim 23  wherein the output transducer is supported only at selected spaced apart locations by the housing. 
     
     
       26. A hearing aid as in  claim 25  which includes spaces between the output transducer and the housing. 
     
     
       27. A hearing aid as in  claim 26  wherein at least some of the spaces are filled with a gas. 
     
     
       28. A hearing aid as in  claim 26  wherein the transducers are oriented so as to be on the order of ninety degrees out of phase with one another.